There are known in the art various embodiments of vacuum sealers for both home and light commercial usage. These sealers are used generally to seal high-density polyethylene, styrene base plastics or other type plastic bags that contain various foods. After sealing the bags containing the food, the food can be frozen or otherwise preserved for later consumption. Fruits, vegetables, meats, sandwiches and even liquid foods such as soups can be stored in sealed plastic bags. A properly sealed bag preserves the flavor, freshness, color and nutrients of the food contained therein. Items other than food can be kept in these sealed bags such as papers to be kept watertight, matches, flower seeds, articles to be kept moth-free in the summer months, shampoos or soaps with proper portions, travel items to be kept secure and to avoid spillage and also photos or other documents to be preserved. Food can be frozen in these bags and protected against freezer burn or can be used in microwave cooking and in-bag cooking.
Many of the prior art sealers such as Applicant's Deni FRESHLOCK (Deni and Freshlock are registered trademarks of Keystone Manufacturing Co. of Buffalo, New York) have been successfully used in the household for a variety of purposes. The Deni FRESHLOCK is described, for example, in "The Gourmet Retailer", April 1990, volume II, Number 4 on page 61. While this type of sealer has many advantages, certain aspects can be substantially improved upon. Not only the Deni FRESHLOCK sealer but also most other home-use sealers use one or two heated wires to both seal and cut the plastic bag. It has been found that these one or two wire sealers do not consistently provide the strongest seal on the bag. This is because a one-wire or two-wire unit requires a dual function for the wire or wires and cannot assign a dedicated specific use for each. Other sealers provide a wire to seal and a cutter blade to cut or sever the bag. This involves including a relatively expensive cutting mechanism in each sealer and an additional step by the user and also including just one more component that can break down or require repair. A home vacuum sealer having improved sealing characteristics and avoiding costly cutting mechanisms would be a substantial improvement in the art.
The sealing units used previously generally utilize a fan to provide the vacuum effect in the unit. The fans used generally have straight fins or blades which do not provide the most efficient vacuum or air movement. Sealers having improved vacuum generating effect would also provide a substantial improvement in the home use vacuum sealers.
One serious problem confronting any sealer of this type is the air flow pattern from the fan through the air nozzle and into the plastic bag. This air flow problem is generally caused by a plurality of reasons. One reason is the height of the unit above the table or work surface. If the sealer is too high the bag will have a substantial drop as it is suspended from the sealer and form an S-like configuration which could impede the flow of air or vacuum effect. Another potential air flow problem could be caused by the lead-in structure for the bag in the interior of the sealer. The less severe the curvature of the bag both inside and outside the vacuum sealer, the less resistance there will be to air flow and subsequent vacuum action. Another potential problem could be caused by insufficient or inefficient air exhaust vents which expel the air from the sealer during the vacuum process. Most air outlets in the prior art vacuum sealers are small and are located in the bottom of the unit which could increase the resistance to air exhausting. It would be desirable to make a unit having a lower profile, better and more efficient exhaust vents, increased vacuuming effect and better balance than those sealers previously available.